1. Field of the Invention
The invention pertains generally to the field of stereoscopic television and, more particularly to a stereoscopic television viewing system in which alternate left and right images are presented to the corresponding left and right eyes of a viewing person in a synchronous using manner optical signals.
2. Description of the Prior Art
While the field of stereoscopic television is a relatively new branch of the electro-optical arts, many schemes and systems have been devised in order that the viewer may be presented with what he conceives to be a three-dimensional or stereo television image. These various systems are characterized by several methods of image separation and recombination including electromechanical shutter devices and devices having electro-optic shutters which are directly connected by wire to the remainder of this stereoscopic television system.
One such device is illustrated and described in a patent to Roese U.S. Pat. No. 3,903,358, issued Sept. 2, 1975, which illustrates and describes a stereoscopic television system which employs a single camera and a beam splitting system to present alternate left and right image inputs to a television monitor. A stereoscopic viewing system is used which includes glasses having left and right PLZT electro-optic light valve lenses the opening and closing of which is controlled in synchronization with the left and right image presentation by the monitor. The left and right presentation of images is made using the interlace pattern of the two scanning fields of the standard TV frame. While this system has proved to be highly successful, the necessity for directly connecting the stereo viewer glasses with the viewer distribution circuit greatly encumbers the activity of the viewing person and also makes it quite difficult for a plurality of viewers to simultaneously view this same stereoscopic television presentation as additional sets of connecting wires must be provided.
Another synchronized stereoscopic television system is illustrated and described in a patent to Hope U.S. Pat. No. 3,621,127 issued Nov. 16, 1971. That system utilizes a high frequency carrier transmitter and receiving system to transmit and receive timed signals which are then utilized to operate a shuttering spectacle such that the left and right eye elements are opened and closed alternately in response to the high frequency signals. While this system eliminates the necessity of direct connection between the spectacles and the control and synchronizing system of the stereoscopic television viewing system there may be unwanted interference from or with other high frequency signals. In addition, the system is nondirectional so that the spectacles operate whether or not the wearer's attention is directed toward the screen.